Foot-powered energy generator

ABSTRACT

A foot-powered energy generation device includes a step plate that moves between an upper position and a lower position in response to the step action of a user. The device also includes an electrical generator, and a gear train that will cause a rotor of the generator to rotate in response to movement of the step plate up and down. A carriage is mechanically interconnected to the step plate and the gear train to cause the rotation of the gear train in response to the step plate motion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent document is a continuation-in-part of U.S. patentapplication Ser. No. 13/873,021, filed Apr. 29, 2013, which claimspriority to U.S. provisional patent application number 61/687 596, filedApr. 27, 2012. The disclosures of each priority application are fullyincorporated by reference.

BACKGROUND

This document relates to wearable systems for generating power for usein charging batteries and portable electronic devices.

As portable electronics like smartphones, GPS systems, wearableelectronic devices, fitness electronics and other electronic deviceshave become ubiquitous; the need to charge such devices has becomeextremely important. Many people around the world have access to cheap,portable electronics but lack a suitable means to charge them.

To date, the most common portable charging solutions are backup batteryand solar powered solutions. However, those solutions require users tocarry additional equipment, and even those solutions only providecharges for a limited period of time. Backup batteries must themselvesbe recharged, and solar powered solutions are only useful duringdaylight hours or when artificial light sources are available.

This document describes methods and systems that are directed to solvingat least some of the problems described above.

SUMMARY

In an embodiment, a foot-powered energy generation device includes astep plate that moves between an upper position and a lower position inresponse to the step action of a user. The device also includes anelectrical generator and a gear train that will cause a rotor of thegenerator to rotate when the step plate moves up and down. A carriage ismechanically interconnected to the step plate and the gear train tocause the rotation of the gear train in response to the step platemotion.

In another embodiment, a foot-powered energy generation device includesa base configured to fit within a footwear item, a step plate having anupper position and a lower position, and a generator comprising a rotor.A gear train comprising a first gear and a second gear is configured sothat rotation of the first gear will cause the second gear to rotate,optionally via one or more intermediary gears. Rotation of the secondgear will cause the rotor to rotate. A carriage is mechanicallyinterconnected to the step plate and the first gear so that the carriagewill cause the first gear to rotate in response to movement of the stepplate between the upper position and the lower position.

Optionally, the device may include a linkage that mechanicallyinterconnects the step plate to the carriage so that when pressure isapplied to the step plate and moves the step plate toward the lowerposition, the linkage will cause the carriage to move in a firstdirection away from a first position. When pressure is released from thestep plate so that the step plate moves up toward the upper position,the linkage will cause the carriage to return to the first position.Optionally, the linkage may comprise a spring that is also configured toreturn the step plate to the upper position when pressure is releasedfrom the step plate. Optionally, the step plate may be integral with ora surface of the linkage. In another option, the step plate may beintegral with the carriage. Any number of step plates may be used.

Optionally, the carriage may have an opening configured to receive andengage the first gear. The opening may have opposing first and secondsides and a lateral dimension between the first and sides. The lateraldimension may larger than a diameter of the first gear so that when thecarriage moves in a first direction away from a first position, thefirst side of the opening will engage the first gear and cause the firstgear to rotate in a direction of rotation. When the carriage moves in asecond direction to return to the first position, the second side of theopening will engage the first gear and cause the first gear to rotate inthe direction of rotation.

In some embodiments, the gear train may include a planetary gear havinga center. If so, the center of the planetary gear and the center of therotor may both rotate around the same axis. The gear train also mayinclude at least one intermediary gear that is positioned and configuredto mechanically interconnect the first gear to the planetary gear. Thegear train may be configured so that each gear in the gear train ispositioned along a plane that is substantially parallel to the base.

Optionally, the device also may include clutch that is configured toengage the carriage with the gear train and disengage the carriage fromthe gear train. Alternatively, the clutch may be configured to cause thefirst gear to be engaged with the second gear when a speed of rotationof the first gear exceeds a threshold, and to cause the first gear to bedisengaged from the second gear when the speed of rotation of the firstgear does not exceed the threshold.

In various embodiments, the generator may be a radial permanent magnetgenerator, an axial permanent magnet generator, or another type ofgenerator.

The device also may include, or it may be, a footwear item, such as ashoe, boot, insole, heel or other housing that is configured to be wornon a foot.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate various views of a first embodiment of afoot-powered energy generation device.

FIGS. 2A and 2B illustrate additional elements of certain components ofthe device of FIG. 1.

FIGS. 3A and 3B illustrate various views of a second embodiment of afoot-powered energy generation device.

FIGS. 4 and 5 illustrate examples of radial generators that the devicemay include.

FIGS. 6-8 illustrate examples of axial generators that the device mayinclude.

FIG. 9 illustrates a third embodiment of a foot-powered energygeneration device.

FIG. 10 illustrates a variation of the embodiment of FIG. 9 with arack-and-pinion arrangement.

FIG. 11 illustrates a variation of the embodiment of FIG. 10 in which analternative linkage is shown.

FIGS. 12 and 13 illustrate additional examples of generators that thesystem may include.

FIGS. 14A and 14B illustrate an example of an electronic circuit thatmay convert the generation device's AC output to DC, and also regulatethe delivery of DC to an external battery.

FIG. 15 illustrates an example shoe having an energy generation deviceincorporated within or under the shoe's insole.

DETAILED DESCRIPTION

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. As used in this document, the term “comprising” means“including, but not limited to.”

As used in this document, the terms “footwear item,” “article offootwear” and the like refer to apparel that is configured to be worn ona foot, as well as components of such apparel. Examples include shoes,boots, sandals, thongs, socks and the like. Examples also includecomponents such as insoles, soles, heels, and the like. In someembodiments, a “footwear item” also may be a prosthesis that isconfigured to replace a foot, or a foot shell that is used with aprosthesis. Footwear may be configured to be worn on human feet, or onanimals such as horses.

As used in this document, the term “mechanically interconnected,” whenused to describe two or more items, means that the items aremechanically related to each other, either by a direct mechanicalconnection or indirectly via one or more other components, so thatmovement of at least one of the items will also cause the other item(s)to move. Mechanically interconnected components need not be connected atall times, so long as they are configured directly or indirectly engagewith each other at some point during operation of the system of whichthey are a part.

As used in this document, the term “portable electronic device” refersto a device that includes electronic components and which requires asource of power to operate. Examples of portable electronic devicesinclude smartphones, global positioning system (GPS), wearableelectronic devices such as smart watches and smart eyeglasses, fitnesselectronics, cameras, media players, laptop computers and electronictablets.

Portable electronic devices like mobile phones and laptops requiresources of power, such as a battery or an active power supply. It can beinconvenient and expensive to constantly need to find a power supply orcarry backup batteries. This document describes a device and system thathelps to solve this problem by harvesting energy from the act of a humantaking a step. The system is wearable in that some or all of it may beattached to or integrated within an item of footwear, such as a boot,shoe or insole.

FIGS. 1A through 1C illustrate a first embodiment, in which afoot-powered energy generation device 10 includes a drive plate 21,pulley system and lever arm that, when actuated, will convert linearmotion to rotational motion that is then used to actuate an electricalgenerator. The system may be sized to fit within the sole, heel, toe boxand/or other components of an article of footwear. The mechanismapplications extend past use in the sole of a shoe.

The drive plate 21 is a movable member that is positioned to receive aheel of a person who is wearing the article of footwear within which thedevice 10 is incorporated. One or more springs 13 are positioned underthe drive plate 21 and serve as biasing members that bias and urge thedrive plate 21 upward to an upper stop position that corresponds to therelaxed position of the spring(s) 13. (For simplicity, this document mayrefer to “one or more springs” using the plural term below.) One or moreside support plates 15 may be positioned along one or more sides of thedrive plate to limit or prevent horizontal (side-to-side) movement ofthe drive plate 21. As shown, a drive link 18 may be positioned under agenerally central area of the drive plate 21 when the drive plate is inthe upper position. The springs 13 may be positioned under a first endarea of the drive plate 21.

When a person steps on the device 10, at least a portion of the driveplate 21 moves downward and the springs 13 are compressed. The driveplate 21 serves as an actuating member that moves from the stop (upper)position to a compressed (lower) position that is closer to the base 26than the stop position of the drive plate 21 is to the base 26. In theembodiment of FIGS. 1A-1C, a first end of the drive plate 21 that isover the springs 13 will move downward, while the second end of thedrive plate (i.e., the end that is on the side opposite the springs)will remain in an upper position. Optionally, the second end may besupported by an axle, pin or other structure 16. For example, asillustrated in FIG. 2A, the second end may also be supported by one ormore springs having different tensile properties than the springs 13 atthe first end. In this way, when the drive plate 21 moves downwardtoward the base 26, the drive plate urges the drive link 18 to move awayfrom the springs 13 in a direction that is generally parallel to thebase 26 and orthogonal to the direction of compression of the springs 13and/or the direction of movement of the drive plate 21. Thus, the driveplate 21 and drive link 18 are mechanically interconnected. The driveplate 21 as shown is positioned to be parallel to the base 26, althoughthis is not a requirement. In some embodiments, the drive plate 21 maybe positioned at an angle with respect to the base 26.

For example, referring to FIGS. 1A-1C and 2A-2B, when a heel strikes thedrive plate 21 over the springs 13, the drive link 18 may move from afirst position further away from the springs 13 to a second positionlocated near (or relatively closer to) the springs 13. The firstlocation of the drive link 18 is its position when the drive plate 21 isin the upper position. The drive link 18 moves to a second location,near the springs 13 (i.e., toward the left in FIG. 1B), when the driveplate 21 is depressed. The drive link 18 may be a wheel, a slidingstructure, a sphere, a cylinder, or any other member that can be movedfrom a first position to a second position. In addition oralternatively, the drive link 18 may angularly pivot about a shaft 17 inresponse to movement of the drive plate 21 from its upper position tothe lower position. The system also may include a second biasing member16 that urges the drive link 18 back to the first position as the driveplate 12 moves toward its upper position. The second biasing member maybe, for example, a spring, an elastic cable, or other member that isattached to a drive link shaft 17 or other components and that pushes orpulls the drive link 18 back to the first position.

The drive link 18 and/or the drive link shaft 17 are connected to apulley system. The pulley system includes a primary pulley shaft 19, asecondary pulley shaft 14, a connecting cable 25 and one or more cablepulleys 23. When the pulley system's cable is moved, the cable causesone or more lever arms 22 to move. Each arm 22 is connected to a geartrain 17 and moves between a first and second position. The cable 25 isdirectly or indirectly secured to the drive link 18 or drive link shaft17 and thus enables movement of the drive link 18 to cause movement ofeach arm 22.

The arm(s) 22 are connected to the gear train 27, and this movement ofthe arms causes movement of the gear train 27. The system also includesan electric generator with at least one armature 32 that is rotatablymounted in a stator. The gear train 27 may include a first gear 28having a shaft that is connected to an arm 22, a second gear 12 having ashaft that is connected to the armature 32, and any number of additionalgears. Movement of the first gear 28 may cause angular movement of thesecond gear 12 in response to movement of the drive link 18. Optionally,the movement of the first gear 28 may correspond to greater angularmovement of the second gear 12. When the arms 22 move from a firstposition to the second position, and then back from the second positionto the first position, the angular directions of rotation of acorresponding armature 32 may be the same for each arm movement or maybe opposite for each arm movement. Thus, the generator may be activatedin response to travel of the drive link 18 from the first position tothe second position, and/or from the second position to the firstposition.

When the arm(s) 22 turn the gear train 27, the gear train is connectedto the armature 32 and thus causes the armature to rotate. The rotationof the armature 32 in the stator generates electric current. The systemalso may include an AC-to-DC conversion circuit, such as a system ofrectifiers and amplifiers that convert to generated current from AC intoDC before the energy is stored in a rechargeable battery.

The device 10 generates power during two phases: when the user presseshis or her foot down in a step, and when the user picks his or her footup in the step. The first is described above as the “stepping phase” andcompression of the drive plate 21. During the second phase, when theuser lifts his or her foot, the user removes pressure from the driveplate 21, causing the system components to return to their initialpositions. One or more reset springs 24 serve as tension springs thatconnect the arms 22 to the base 26. Movement of the arms from theirfirst position to their second position will load the reset springs 24as the drive plate 21 moves to the lower position. When the drive plate21 returns from the lower position to the upper (stop) position, thereset springs 24 return to their first position and push the electricgenerator in the opposite direction, and support spring(s) 13 push thedrive plate 21 upwards. The motion ensures that the cable 25 remainstaught. Thus, the system may generate energy throughout each stage ofperson's typical walking pattern.

The base plate 26 and a center support plate outline the area of themechanism and support all components. The size and shape of the baseplate 26 may vary based on the particular application or size of thewearer's shoe. The system components may be provided in a casing thatfits within a profile of an orthotic insert, and which can be embeddedwithin an insert or shoe sole. A mechanically drivable energy convertermay be secured to the casing and connected to an electrical storagedevice. Alternatively or in addition, a storage battery may beelectrically connected to the generator to store electrical energy inresponse to activation of the generator.

FIGS. 3A and 3B illustrate an alternate embodiment of a foot-poweredenergy generator 50. FIG. 3A illustrates a perspective view of the “top”of the device (the top being the surface onto which a user will placehis or her foot), while FIG. 3B illustrates a perspective view of the“bottom,” i.e., the lower surface that includes the base 57 of a housingof the device. The illustrations of FIGS. 3A and 3B do not show allcomponents of the device's housing so that certain interior componentsmay be shown and described here. Although designated as “top” and“bottom” for the purpose of discussion, the embodiments shown in FIGS.3A, 3B, and other figures may be used in either direction. A housing mayor may not be used in practice. The device 50 is sized to fit within atleast a heel portion of an article of footwear, prosthetic foot orinsole. Thus, as shown the device's base 57 optionally may be curved tocorrespond to the shape of a heel of an item of footwear.

The top portion of the device's housing includes a moveable step plate55 that is supported at least in part by one or more linkages 53, 54that are mechanically interconnected to a carriage 63. Thus, the stepplate 55 is also mechanically interconnected to the carriage 63. Thestep plate 55 is not shown in FIG. 3A so that features underneath it maybe seen, but step plate 55 is illustrated in FIG. 3B. The linkages 53,54, which may be semi-rigid, resilient members such as leaf springs,carriage springs and the like that are directly or indirectly connectedto the primary carriage 63, either at all times or only when moved bythe step plate 55. When a person applies pressure to the step plate 55by stepping downward, the step plate will move downward and cause thelinkage(s) 53, 54 to move in a direction that urges the primary carriageaway from a first position (i.e., its original or rest position) in adirection that is parallel to the base 57. For example, the carriage 63may move away from the heel portion of the base toward a second orextended position when the step plate 55 is depressed by a user steppingdownward onto the device.

Although the illustrations show the step plate as being at the top ofthe device, in various embodiments it may be positioned near the bottomor at an interior location, so long as it moves in a direction thatcauses the carriage to move when the wearer applies pressure to theplate.

When the user picks up his or her foot and thus releases pressure fromthe step plate 55, the linkages 53, 54 or other tensile members willurge the step plate 55 back to an upward position, and one or more resetsprings 61, 62 may push the carriage back to its first position. Thereset spring(s) 61, 62 as shown are positioned between the primarycarriage and the non-heel portion of the device and are thus compressedwhen the carriage 63 moves to the second position. In an alternateembodiment, reset spring(s) 61, 62 may be mechanically connected to theprimary carriage and a heel portion of the device's housing so that theyextend when the carriage 63 moves to the second position. Either way,when the spring(s) 61, 62 return to a position of rest, the carriage 63will return to its first position. In an additional embodiment, when thelinkages 53, 54 are leaf springs, the leaf springs may provide resetfunction and pull the carriage back to its first position when pressureis released from the step plate 55. When this happens, both the resetsprings 61, 62 and the leaf springs 53, 54 may urge the carriage back toits first position, or the reset springs 61, 62 may not be required atall and may be omitted.

FIG. 3B illustrates that the carriage 63 may include or be mechanicallyinterconnected to a unidirectional motion component 64. Theunidirectional motion component 64 is a structure that is capable ofmoving in at least two directions, and which is also mechanicallyinterconnected to one or more gears of a gear train so that when theunidirectional motion component 64 moves in any of its configureddirections, the connected gears will also turn. As shown in FIG. 3B, theunidirectional motion component 64 may include an opening 60 with twosides that are positioned at an angle that is not parallel to that ofthe direction of motion of the carriage. For example, the angle may beapproximately 45 degrees, or between about 30 degrees and about 60degrees, or between about 15 degrees and about 75 degrees. Other anglesare possible. Each side of the opening 60 may include teeth that aresized and positioned to engage the teeth of a first gear 52 of the geartrain, which as shown may be a planetary gear. The teeth may be of thefirst gear 52 itself or of an axle that is integral with the gear asshown in FIG. 3B. As shown the first gear 52 may be a planetary gearthat rotates about the same axis as that of a second gear 58.Alternatively, instead of teeth, the opening 60, first gear 52 and/orsecond gear 58 may be made of or coated with a non-smooth surface sothat the opening may move the gear by friction. (In this description,when terms such as “first,” “second” “final” and the like are used torefer to gears, they do not necessarily require the gear to be first orfinal in a sequence of gears. Rather, the terms are merely used todistinguish the gears and define their positions relative to each otherin a turning sequence.)

The opening 60 is wider than the engaged component of the first gear 58so that both sides of the opening 60 will not engage the gear at thesame time. Thus, when the carriage 63 moves in a first direction awayfrom the heel, a first side of the opening 60 will engage the first gear52 and cause the first gear 52 to rotate in a first direction (i.e.,clockwise or counterclockwise). Because of the unidirectional motioncomponent 64, when the carriage moves in the opposite direction toreturn toward the heel, the opposite side of the opening 60 of theunidirectional motion component will engage the first gear 52 and causethe first gear 52 to rotate in the same direction. Thus, the carriage 63serves as a continuous drive train for the first gear 52 as it ensuresthat the first gear 52 continues to turn in a single direction as thecarriage 63 moves back and forth while the wearer walks, runs orotherwise repeatedly places pressure on and removes pressure from thetop of the device.

In an alternative embodiment, the carriage 63 may include or simply beone or more linear gear bars that engage the circular first gear 52 in arack and pinion arrangement in which the gear bar(s) of the carriage arethe rack and the first gear 52 is the pinion. In this embodiment, a pairof gear bars may be angled and positioned to correspond to the locationof the opening 60 of the carriage 63 as shown in FIG. 3B so that thefirst gear 52 will rotate in a single direction of rotation during eachphase of the user's stepping motion. Alternatively, a single gear barmay move in a direction that is parallel to that of the base, such asfrom heel to toe when pressure is applied to the drive plate and fromtoe to heel when pressure is released from the drive plate (or viceversa). In this way, the gear bar may cause the first gear toalternatively rotate in the clockwise and counterclockwise directions atany time when the user's foot moves upward or downward on the driveplate. Alternatively, a clutch may release the gear bar from the firstgear on one of the strokes and engage the gear bar with the first gearon the other stroke so that the first gear alternates between a singledirection turn and a neutral position.

The first gear 52, when rotated, may engage and rotate a final gear 59,optionally via one or more intermediary gears 69. The final gear 59 maybe connected to a generator 66 so that the center of the final gearrevolves around the same axis as that around which the center of therotor of the generator 66 revolves as shown. Optionally, instead of orin addition to sharing an axis of rotation with the generator 66, thefinal gear 59 may be integral with the rotor of the generator 66. Asanother alternative, the generator 66 may be a radial generator withteeth that interact with the final gear 59 instead of connected to thefinal gear via an axle. In various embodiments, final gear 59 may be aplanetary gear system or a smaller gear that engages the rotor in astacked or non-stacked arrangement, either directly such as in a rackand pinion arrangement or indirectly via one or more other components.Such an embodiment will be discussed in more detail below in the textrelating to FIG. 9. In any of these embodiments, the gears serve as agear train that will drive the generator 66. The gear train may bepositioned along a plane that is parallel to that of the base so thatthe when the step plate 55 moves up and down under the wearer's heel,rotational motion is transferred to the final gear 59 and generator 66,which may be generally positioned in an instep area of the footwearitem, or otherwise closer than the first gear is to the toe box of thefootwear item.

In embodiments that have a final gear 59, the final gear 59 may have adiameter that is smaller than that of the second gear 58 and/orintermediary gear(s) 69 as shown. For example, the turning ratio of thefinal gear to the first gear may be approximately 30:1, approximately40:1, or greater. In embodiments in which first gear 59 is not aplanetary gear, smaller gear ratios such as approximately 20:1 may beimplemented. Other ratios are possible. AC power generated by thegenerator may be transferred to an external battery via one or morepower ports to which one or more electrical conductors may be connected.

Optionally, any gear in the system also may be connected to a clutch 56that is configured to engage the connected gear (in the example shown,final gear 59) with the rest of the gear train only when the first gearis rotating according to at least a minimum speed. If the speed (e.g.,rotations per minute or rotations per second, etc.) is lower than thethreshold, the clutch 56 may disengage the connected gear from the othergears in the gear train. For example, disengagement may occur by theclutch 56 moving the final gear 59 in a lateral direction away from thefirst gear 52 (e.g., toward the toe), and engagement may occur by theclutch 56 moving the final gear 59 in a lateral direction toward thefirst gear 52 or the intermediary gear 69. Alternatively, the clutch 56may be configured to engage and disengage the unidirectional motioncomponent 64 with the first gear 52, such as by moving either the firstgear 52 or the unidirectional motion component 64 up or down. In thisalternative, the clutch may be configured to (i) engage theunidirectional motion component 64 with the first gear 52 when the speedof motion of the carriage, the speed of motion of the step plate, orpressure applied to the step plate exceeds a threshold; and (ii)disengage the unidirectional motion component 64 from the first gear 52when the speed of motion of the carriage, the speed of motion of thestep plate, or pressure applied to the step plate does not exceed thethreshold. The clutch may be embodied in a suitable clutch mechanism,such as a multiple plate clutch, a one way bearing (e.g., a rollerclutch or sprag clutch), or other types of clutches.

The generator 66 may be a radial generator as shown in FIG. 3B, or thesystem may incorporate other permanent magnet generators or other typesof generators. For example, the system may incorporate a permanentmagnet generator that includes (i) a rotor that houses a set of magnetsand (ii) a stator that holds stationary coils. The magnetic flux emittedfrom the magnets may move from pole to pole, and be arranged along therotor such that the resulting magnetic field moves through the geometryof the coil, inducing a current.

As an example, FIG. 4 illustrates an internal radial generator 466 inwhich the rotor 473, which includes a central hub and an externalcylindrical sidewall comprising magnets 471 configured in a sequence ofalternating polarity, is positioned inside of the stator 470 and acts asa drum that rotates within the stator 470. FIG. 5 illustrates anexternal radial generator 566 in which the rotor 573 is positionedoutside of the stator 570 and thus surrounds the stator and acts as adrum that contains and rotates around the stator 570. In the externalradial generator 566, the magnets 571 are positioned on an internalcylindrical sidewall of the rotor 473. In either embodiment, variouscomponents may be plastic, while others may be ferrous or other metallicstructures. For example, the stators may be made of steel or othermaterials. Various types of magnets may be used, such as neodymiummagnets.

In an alternate embodiment, an axial permanent magnet generator may beused to provide a lower (i.e., flatter) profile than a radial generator.FIGS. 6-8 illustrate examples. For example FIG. 6 illustrates a singleaxial permanent magnet generator 666 in which the rotor 673 is a dischaving a circular surface on which a set of magnets 671 are arranged ina spoke fashion to extend from a central hub with alternatingpolarities. The rotor 673 faces the stator, and the stator 670 also hasa central hub that is positioned along the same central axis as that ofthe rotor 673. FIG. 7 illustrates a double axial generator 766 in whichthe rotor 773 is positioned between two stators 770, 780 and rotatesabout central axis that the rotor shares in common with the stators.FIG. 8 illustrates a double axial generator 866 with stacked stators inwhich two stators 870, 880 are positioned adjacent to each other andbetween a pair of rotors 873, 883. The rotors 873, 883 rotate around acentral axis that they share in common with the stacked stators 873,883. In each of these embodiments, the stators may be coreless in thatthe coils may be embedded in a resin rather than fixed in place withsteel.

FIG. 9 illustrates an embodiment in which the device 900 includes a geartrain with no planetary gear, but instead a first gear 959 that engagesa second gear 952, which in turn engages the rotor 981 of a generator966. The first gear 959 includes an axle 902 that is configured to beturned in a single direction of rotation in response to movement of thecarriage 963 in multiple directions. The axle 902 also may includeprongs so that first gear 959 is a gear stack in which the axle 902 isone gear component of the stack. When the wearer steps down on the stepplate(s) (not shown), one or more linkages 953, 954 such as springsunder the step plate will push the carriage 960 to move in a firstdirection (e.g., away from the heel). As with other embodiments, thelinkages 953, 954 may be semi-rigid resilient members such as leafsprings, carriage springs and the like. Various components may besupported by a base 955. Any number of step plates may be used invarious embodiments. A base 957 supports the various components asshown. This and any other embodiment also may include one or morefriction reducing pads 966 a, 966 b that are affixed to a top area ofthe device's housing (e.g., if 955 is a base instead of a step plate), abottom area of the device's housing, or both. The friction reducing padsmay be made of any suitable non-skid material, such as rubber, felt, anadhesive, various polymers and the like, any of which may have ananti-skid texture to help hold the device in place in the wearer's shoe.

When the wearer steps up, the step plate(s) will rise and the resilientmembers will pull the carriage 963 in a second direction (e.g., towardthe heel). The opening 960 of the carriage 963 includes a first sectionand an offset second section that provide two opposing ledges thatengage prongs that extend from the axle 902. In this way, the carriageand axle together provide a unidirectional motion component configuredto turn the gear 959 in a single direction of rotation, although thisconfiguration is only shown by example. Other configurations can alsoturn the first gear in a single direction and are included within thescope of the invention. FIG. 10 illustrates an example of a rack andpinion arrangement in which the carriage opening is lined with a gearbar 983 that serves as a rack and the axle 992 serves as a pinion. Inaddition, FIG. 10 shows that one or more portions of the carriage993/995 may serve as the step or drive plate so that a separate stepplate is not needed. Such arrangements may be used in any of theembodiments described and shown in this document, and various componentsof other embodiments (such as a clutch) may be included in thisembodiment. Indeed, any component of any embodiment shown in thisdocument may be interchanged with components of other shown embodimens.

Returning to FIG. 9, when the first gear 959 turns, it will engage acomponent of the second gear 952, such as an axle 963 that is toothed sothat the second gear 952 is a stack, of which the axle 953 is acomponent. The second gear 952, when turned, engages and turns the rotor981 of the generator 966.

FIG. 11 illustrates an alternate embodiment in which the carriage 1153is positioned above the base 1157 and under the gear train. The linkages1154, 1155 in this embodiment are semi-circular resilient members orleaf springs. The upper surface of each linkage may be under a stepplate, or the upper surface of the linkage itself may serve as the stepplate. When a person steps on the device, the linkages 1154, 1155 andtheir corresponding step plate(s) compress into a lower position andmove the carriage 1153 away from the heel. When the person raises his orher foot the linkages 1154, 1155 decompress, return to an upperposition, and move the carriage 1153 back toward the heel. Bothmovements cause the first gear 1159 to rotate. The first gear 1159engages and rotates a second or final gear 1152, which directly orindirectly engages the rotor of the generator 1166, optionally via oneor more components such as a hub or any number of intermediary gears1180. The final gear 1152 turns the rotor of the generator 1166. Thearrangements of FIG. 11 may be used in any of the embodiments describedand shown in this document, and various components of other embodiments(such as a clutch) may be included in this embodiment.

FIG. 12 illustrates an axial generator embodiment of the generator 1266that includes a stator 1270 and a rotor 1273, each of which areconfigured as circular plates of substantially equal diameter. The rotorincludes a set of magnets 1271 positioned around the rotor, optionallypositioned as spokes extending from a central hub 1280. The stator androtor are stacked, with a set of coils 1275 positioned between thestator and rotor. The coils 1275 may be arranged on the stator in acircle around the hub 1280. The hub may include an extending member (981in FIG. 9) that will engage the gear train and the rotor and thus turnthe rotor in response to rotation of the gear train. Other axialgenerator configurations are possible.

FIG. 13 illustrates a radial generator embodiment in which the generator1366 includes a circular rotor 1370 and a circular stator 1373, in whichthe stator 1373 is positioned within the rotor and each share a commoncentral hub 1380. The rotor includes a set of magnets 1371 positionedaround the rotor's circumference, optionally positioned as spokesextending from the central hub 1380. A set of coils 1375 positionedaround an inner wall of the rotor 1370, optionally as spokes extendinginward toward the stator. The hub may include an extending member (e.g.,981 in FIG. 9) that will engage the gear train and the rotor and thusturn the rotor in response to rotation of the gear train. Other radialgenerator configurations are possible

The systems of any of these embodiments also may include an AC-to-DCconversion circuit, such as a system of rectifiers and amplifiers thatconvert to generated current from AC into DC before the energy is storedin a rechargeable battery. FIGS. 14A and 14B are a circuit diagram ofvarious example components of a charging circuit that may be included ina battery unit. The circuit receives power via a set of contacts 1401that are connected to the generator via one or more conductive elements.A full bridge rectifier 1403 converts the input alternating current (AC)to direct current (DC).

The voltage of the rectifier 1403 output may not be sufficient to chargean energy storage device, and it may be susceptible to power spikesduring operation. To address this, a first regulating circuit 1405 mayreceive the rectifier output and regulate its voltage to a levelcorresponding to that of the energy storage device's rated inputvoltage. The regulating circuit 1405 may increase the voltage from therectifier when necessary, reduces voltage during spikes, or both. Insome embodiments, the first regulating circuit may be a buck-boostconverter. For example, when used with certain lithium polymer (LiPo)batteries, the regulating circuit may include a buck-boost converterthat yields a regulated output voltage in a range of approximately 3.7volts to approximately 4.2 volts. Other voltage ratings and ranges arepossible, typically depending on the rating of the battery that is usedwith the system.

During a charging operation, the output of the first regulating circuitmay lead to a charging circuit 1411 that may be configured to regulatethe delivery of current to an external battery 1431. When the chargingcircuit 1411, which as shown is an integrated circuit such as thoseknown now or in the future to persons of skill in the art, detects thatthe battery unit voltage is less than a threshold level, it may reducethe charging current delivered to the battery 1431, and it may increasethe current when the voltage rises to at least the threshold. Thesethresholds may be set by one or more external resistors. When thecharging circuit 1411 detects that the battery 1431 is fully charged orwithin a threshold amount of being fully charged, the charging circuit1411 may switch to an end of charge condition and reduce or stopdelivering charge to the battery 1431. The charging circuit 1411 alsomay include outputs for interfacing with LEDs 1415 or other indicatorsthat provide a visual indicator when the device is charging a battery.

During a discharging operation, power from the battery 1431 may passthrough a second regulating circuit 1421 that regulates the voltage ofthe level that is required for a load 1435, such as a mobile electronicdevice or device battery that is being charged. In some embodiments, thesecond regulating circuit 1421 may include a boost circuit thatregulates a charge to remain above a threshold level, a buck circuitthat regulates a charge to remain below a threshold level, or abuck/boost converter that regulates a charge to remain within an upperand a lower threshold. The load 1435 may be connected to the batteryunit via an electrical connector such as a Universal Serial Bus (USB),mini-USB, micro-USB, Lightning or other connector. The circuit also mayinclude a shock overcurrent and electrostatic discharge protectioncircuit 1423, such as a variable resistor in combination with a filteras shown, to provide an additional level of protection during extremeelectrical events.

In various embodiments, the overall profile of the device is smallenough to fit comfortably within an insole, sole, or heel of an articleof footwear. For example, the device may have a longest dimension (fromheel area to toe or instep area) of about 3.1 inches, and widest widthdimension that is no more than 2.5 inches. The uncompressed height ofthe device may be no more than 0.5 inches. Other sizes are possible.Optionally, the step plate may be separate from the device's housing,and/or the step plate may form part of the sole or insole. Otherconfigurations are possible.

FIG. 15 illustrates an example shoe 1510 having an energy generationmechanism embedded within or under the shoe's insole 1512. The energygeneration mechanism may be one such as those described above, orvariations of such a mechanism, that generate energy in response tobeing activated by a human stepping action. The energy generationmechanism may be embedded within the insole as shown, or within anothercomponent of the shoe, such as the sole. When this document uses theterm “shoe,” it is intended to generally refer to any item of footwear,including but not limited to a shoe, boot, sandal, sock or otherfootwear item.

A power cord 1514 leads from the energy generation mechanism via a port1515 in the insole 1512 or other shoe component to an energy storageunit 1520. The port 1515 will be configured to receive the power cord1514 and direct power generated by the energy generating device to thepower cord 1514 for transfer to an energy storage device such as abattery. For example, the port may include one or more terminals, pins,or other structures that are configured to receive and interconnect withthe power cord.

The power cord 1514 may be equipped with a plug 1516 so that it may beremoved from the storage unit 1520. In various embodiments, the powercord 1514 may include one or more conductors surrounded by an insulatingmaterial. The cord is a conductor and may be round, oval shaped, or insome embodiments shaped so that a side of the cord having a widestdimension abuts the wearer's foot while a side having a shorterdimension extends away from the foot. This relatively flat shape mayresult in more comfort for the user within the shoe. In addition, theport 1515 may be positioned on a side of the insole in a locationbetween the heel area and the ball of the wearer's foot, and in someembodiments under the instep and/or in the area of the medial arches ofthe wearer's foot. In this way, the wire may extend upward from theinsole in a location that is in proximate and in front of the ball ofthe wearer's ankle (i.e., the medial malleolus or the lateral malleolus)so that the wire does not cause discomfort to the wearer. Otherlocations are possible.

The power storage unit 1520 may include features that enable it to beremovably attached to a shoelace 1518 or other component of the shoe1510. Alternatively, the power storage device 1520 may be removablyattached to another portion of the shoe, or to a separate structure suchas wearable securing band. As another alternative, the cord 1514 may belong enough to permit the power storage device 1520 to be placed withina pocket of, or otherwise attached to, another article of clothing suchas pants, shorts, a belt, a jacket, or the like.

The various components of the energy generation device may be made ofmetals, metallic alloys, composites, rubber, or plastics. For example,one embodiment may use aluminum for the base and drive plates, axles,and lever arms, while other parts may be made of plastic.

The features and function described above, as well as alternatives, maybe combined into many other different systems or applications. Variouspresently unforeseen or unanticipated alternatives, modifications,variations or improvements may be made by those skilled in the art, eachof which is also intended to be encompassed by the disclosedembodiments.

1. A foot-powered energy generation device, comprising: a baseconfigured to fit within a footwear item; a step plate having an upperposition and a lower position; a generator comprising a rotor; a geartrain comprising a first gear and a second gear that are configured sothat rotation of the first gear will cause the second gear to rotate,and rotation of the second gear will cause the rotor to rotate; and acarriage that is mechanically interconnected to the step plate and thefirst gear so that the carriage will cause the first gear to rotate inresponse to movement of the step plate between the upper position andthe lower position.
 2. The device of claim 1, further comprising: alinkage that mechanically interconnects the step plate to the carriageso that: when pressure is applied to the step plate so that the stepplate moves toward the lower position, the linkage will cause thecarriage to move in a first direction away from a first position, andwhen pressure is released from the step plate so that the step platemoves up toward the upper position, the linkage will cause the carriageto return to the first position.
 3. The device of claim 2, wherein thelinkage comprises a spring that is also configured to return the stepplate to the upper position when pressure is released from the stepplate.
 4. The device of claim 1, wherein: the carriage comprises anopening configured to receive and engage the first gear; the openingcomprises opposing first and second sides and a lateral dimensionbetween the first and sides, wherein the lateral dimension is largerthan a diameter of the first gear so that: when the carriage moves in afirst direction away from a first position, the first side of theopening will engage the first gear and cause the first gear to rotate ina direction of rotation, and when the carriage moves in a seconddirection to return to the first position, the second side of theopening will engage the first gear and cause the first gear to rotate inthe direction of rotation.
 5. The device of claim 1, wherein: the secondgear comprises a planetary gear having a center; and the device alsocomprises an axis about which the center of the planetary gear and acenter of the rotor both rotate.
 6. The device of claim 1, furthercomprising a clutch that is configured to engage the carriage with thegear train and disengage the carriage from the gear train.
 7. The deviceof claim 1, further comprising a clutch that is configured to cause thefirst gear to be engaged with the second gear when a speed of rotationof the first gear exceeds a threshold; and cause the first gear to bedisengaged from the second gear when the speed of rotation of the firstgear does not exceed the threshold.
 8. The device of claim 1, whereinthe generator comprises a radial permanent magnet generator or an axialpermanent magnet generator.
 9. The device of claim 5, wherein: the geartrain also comprises at least one intermediary gear that is positionedand configured to mechanically interconnect the first gear to theplanetary gear; and the gear train is configured so that each gear inthe gear train is positioned along a plane that is substantiallyparallel to the base.
 10. The device of claim 1, further comprising thefootwear item, and wherein the footwear item comprises an insole or aheel.
 11. The device of claim 1, wherein the step plate comprises asurface of a linkage that mechanically interconnects the step plate tothe carriage so that: when pressure is applied to the linkage so thatthe linkage is compressed, the linkage will cause the carriage to movein a first direction away from a first position, and when pressure isreleased from the step plate so that the step plate moves up toward theupper position, the linkage will cause the carriage to return to thefirst position.
 12. A footwear item having energy generating capability,comprising: a housing that is configured to be worn on a foot,comprising: a step plate having an upper position and a lower position,an electrical generator comprising a rotor, a gear train that is engagedwith the rotor so that rotation of at least a portion of the gear trainwill cause the rotor to rotate, and a carriage that is mechanicallyinterconnected to the step plate and the gear train so that the carriagewill cause components of the gear train to rotate in response tomovement of the step plate between the upper position and the lowerposition.
 13. The footwear item of claim 12, wherein the wearablehousing comprises an insole, a heel or a sole.
 14. The footwear item ofclaim 12, further comprising: a linkage that mechanically interconnectsthe step plate to the carriage so that: when pressure is applied to thestep plate so that the moves toward the lower position, the linkage willcause the carriage to move in a first direction, and when pressure isreleased from the step plate, the step plate moves up toward the upperposition, and the linkage will cause the carriage to return to thesecond position.
 15. The footwear item of claim 14, wherein the linkagecomprises a spring that is also configured to move the step plate towardthe upper position when pressure is released from the step plate. 16.The footwear item of claim 12, wherein: the carriage comprises anopening configured to receive and engage a first gear of the gear train;the opening is configured to receive the first gear and comprisesopposing first and second sides and a lateral dimension between thefirst and sides, wherein the lateral dimension is larger than a diameterof the first gear so that: when the carriage moves in a first directionaway from a first position, the first side of the opening will engagethe first gear and cause the first gear to rotate in a direction ofrotation, and when the carriage moves in a second direction to return tothe first position, the second side of the opening will engage the firstgear and also cause the first gear to rotate in the direction ofrotation.
 17. The footwear item of claim 12, wherein: the gear traincomprises a planetary gear having a center; and the device alsocomprises an axis about which the center of the planetary gear and acenter of the rotor both rotate.
 18. The footwear item of claim 12,further comprising a clutch that is configured to engage the carriagewith the gear train and disengage the carriage from the gear train. 19.The footwear item of claim 12, further comprising a clutch that isconfigured to: cause a first gear of the gear train to engage withanother component of the gear train when a speed of rotation of thefirst gear exceeds a threshold; and cause the first gear to disengagefrom the other component of the gear train when the speed of rotationdoes not exceed the threshold.
 20. The device of claim 12, wherein theelectrical generator comprises a radial permanent magnet generator or anaxial permanent magnet generator.
 21. The footwear item of claim 18,wherein: the gear train also comprises a first gear and at least oneintermediary gear that is positioned and configured to mechanicallyinterconnect the first gear to the planetary gear; and the gear train isconfigured so that each gear in the gear train is positioned along aplane that is substantially parallel to the base.
 22. The footwear itemof claim 12, wherein the step plate comprises a surface of a linkagethat mechanically interconnects the step plate to the carriage so that:when pressure is applied to the linkage so that the linkage iscompressed, the linkage will cause the carriage to move in a firstdirection away from a first position, and when pressure is released fromthe step plate so that the step plate moves up toward the upperposition, the linkage will cause the carriage to return to the firstposition.
 23. The footwear item of claim 12, further comprising a powerport configured to direct energy that is generated by the generator to aconductor for delivery to an energy storage device.